Vacuum-pan.



, I Guswfim W )9 No. 868,275. f PATENTED 00115, 190?.

- P. G. KAISER. I

VACUUM PAN.

APPLICATION FILED JAN. 31, mm.

3 SHEETS-SHEET l.

No 868,275. ,PATENTED m. 15, 1907.

P. e. KAI Sm.

VACUUM PAN.

LPPLIUATIOH rump um. 31. 1907.

' a SHEETS-SHEET 2.

PATENTED OCT. 15, 1907..

P. G. KAISER. V VAGUUM PAN. APPLICATION FILED JAN. 31, 1907.

' 3 SHEETS-SHEET 3.

UNITED STATES lAUL GUSTAV KAISER,

PATENT OFFICE,

OF CHICAGO, ILLINOIS.

VACUUM-PAN.

Specification of Letters Patent.

Patented Oct. 15, 1907.

' Application filed January 31,1907. Serial No. 355,104.

county of Cook and State of Illinois, have invented cer-.

tain new and useful Improvements in Vacuum-Pans; and I do hereby declare that the following is a full, clear, and exact descriptionthereof, reference being bad to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

lhis invention relates to an improved evaporator or vacuum pan and more particularly to the circulating tubes-therein, the object being to promote circulation of the fluid in such vacuum pan or evaporator and thus increase the efficiency of the device. I The embodiment of my in.- v uition herein illustra'ted is of a type of vacuum pan or evaporator peculiarly adapted for use in soap families for the treating of spent which the liquid to be treated passes into a lower eomi as lye; but it will be manifest that my invention is adapt cdand applicable to many other uses.

In devices 01' this general type heretofore in use, in

pertinent thence upwardly through an intermediate heating compartment denominated a steam-chest, and thence into an upper compartment, it has been found desirable to employ, for the passage for the liquid through the steam-chest, or intermediate compartment, a plurality of small uprightcirculating tubes, thus dividing the liquid in its upward passage into a plurality of relatively small columns eadh of which is subjected to the heat during its upward passage through the steamchest and thereby the more readily heated to the boiling point. Spent lye for example contains in solution glycerin and salt, and the purpose of thus treating the lye is to separate these ingredients and to first effect precipitation of the salt and subsequently the recovery of the glycerin. In vacuum pans made as described, itis iound that. the circulation becomes very imperf ct, that abnormal o1 undesirable currents al't 'formed by the circulating tubes of thostiiinu-hest,,through some of which'th e l'iiliiidis passing upWardly,.whihthrough others of the liquid is passing downwardly to the chamber below. It is also found that the salt'prr-r-ipitated' the boiling action of the liquid al't'ulniilates unevenly in the evaporatm ,"clogging the circulating tubes and ultimately stopping some of-tlu-m, generally on one side or over a considerable area of the steamchest, thereby reducing the number of effective pasfsagesthrough the steam-chest very considerably and hing the el-licioncy of the evawrator or vacuum dimim orimedy these and other defer-ts in previously t'xistiiig structures'l provide an auxiliary or return tube in each ,circulatin tupc ns-well as other derives horo- R H I I,

matter referred co/ whereby each sop-arithpassage through the steam-chest willalford acom'plete circulation of the liquid, such circulation being effected by the use of the auxiliary tubes located within the several circulatory tubes whereby is provided upward pas sages separate and distinct from the downward or reof my'invention will be more'lully understood by reference to the accompanying drawings in which,

e Figure 1 represents in vertical sectional elevation, 'a vacuum pan embodying my invention, the same being tal or transverse section of the vacuum pan, taken upon the line 2-2 of Fig. .1, looking in the direction indicated by the arrows. Fig. 3 is an enlarged vertical section .of a portion of the upper and lower plates of the auxiliary tube therein. Fig. 4 is a horizontal sectional detail view'oi' the device shown in Fig. 3, taken upon the line 4-4 of Fig. 3, but made on a larger scale. Fig. 5 is a view similar to thatot Fig. 1- showing a modifiea-' salt or other precipitate extracted from the liquid under treatment. 3 I

As shown in said drawings, A indica tors, as a whole,

which rest upon iixod I-beams A l The body or shell A is closed at its top" by a top wall or head A and at its the shell A by rivets or otherwise.

three comparl-nunits by two transverse plates or partitions ll ll, secured by rivets or otherwise to the shell .A and which form respectively the upper and the lower, walls of an intermediate co1npai'tiricht constitutiug'a steam-chest. t-.

Ear-hot the partitions ll 13' is provided with a. plurality of openings arranged in vertical al-iuclu'ent. and adapted upright. circulating tubes F F, as clearly indicated in. Figs. l. 3 and 'lhese circulating tubes form open the upper compartment llthrough 't heiutermediatc stezun-chest in any other desirable manner. .ln each of the tubes 1 is located a smaller tube 1*; arranged concentrically in said tubes F.

indicates an inlet pipe leading from a sourcoof steam supply and cornmunicirtiug with the interior of the steam-chest 0 whereby steam illbc -.livered to said stean'i-chest and circulate therein around the outside. of tho. tubes-F in such manner that any liquid through from said steam and thus the temperature of v Said tubes may be secured in the partitions B likby expanding theends ol the tubes or 100 passing through said tubes will absorb the heat there-Q turn passages for the liquid. These and other features taken upon the line 1-1 of Fig. 2. Fig. 2is a horizon.- 6 5 steamchest showing a singlecirculating tube and the '70 tion at the lower end of the vacuum pan to receive the the cylindri 'c bodyor shell of the evaporator or vacuum pan which provided with supporting brackets a '80 bottom by a bottom wallor head A, each secured to The interior of the cylindricshell Ais divided into I) indicates the lower compartment of the e raporatoriuul l9 the upper compartment thereof.

to receive the upper and lower. ends respectivel'yi of conduits or passages from the lower compartment D'to said liquid will be raised and the proper boiling action of said liquid will ensue. Leading from the opposite side of the steam-chest C is a valved drain pipe 0*.

At the upper end of the vacuum pan is a horizontal battle-plate o provided with a central opening a and suspended from said haflle-plate a by bolts or rods a is a smaller central battle-plate 21'. Connected with said top plate A is a passage or conduits through which the fumes, vapors and gases are permitted to escape. Said passage leads to a condenser, by the operation of which the gases escaping from theapparatus are condensed and removed and a partial vacuum maintained in the vacuum pan. Near the top of the vacuum pan, and preferably between the baflle plate n and the plate A is an inlet a .through which water maybe admitted to the interior of the pan A whenever it becomes necessary to wash out and clean the interior of said pan. D indicates a valved inlet pipe communicating with the lower compartment D through which pipe the spent lye, or'other material to be treated, is delivered to said compartment D. In practice, it has been found that this inlet pipe D maybe conveniently used as an outlet, inasmuch as'during the treatment ol the spent lye or othenmateriahsalt or other solids are precipitated in the lower compartment D. It is desirable to drain ofisueh liquid as remainson the top of the precipitated. salt and the pipe D affords a convan ient outlet for said liquid. Furthermore, said pipe I) removable cover DF.

is shown as branched, eacli branch being provided with a valve, and the said branches enteringthe compartment D at differentlevels. [like pprpose of this construction is to permit the liquid to be drawn from dificrent levels according to the amount of salt which may be present. The precipitated salt is taken from said compartment D through a manhole provided with a The compartment E is likewise providcd with a manholethrough which an operator may enter the pan for the .purpose of cleaning the interior thereof, said manhole having a removable cover D.

I) indicates a valved pipe or conduit connected with the bottom wall iiinf the-vacuum pan, communi- 'cating with the compartment D and suitably connected with a sewer or drain, whereby the washout water brought into the pan A through the conduit 0? may be drained off and pass to a sewer. y l

O designates a'steam pipe connected with the main a steam supply pipe G and opening into the compartvalve 1: is opened and steam allowed to enter and fill the pan, displacing the air therein and forcing it out through the passage a. The valve 0 is then closed and condensation of the steam escaping through the passage a creates a substantial vacuum in the apparatus. During the continued operation of thopau, the gases produccd by the evaporation. oi the contents thereof are condensed and removed and a substantial vacuum thereby maintained in the pan. At thc,cnd of the evaporating operation, air is admitted to the apparatus and thevacuum therein destroyed by means of a'valve 'cover D to be opened,.forwhen a partialvacuum exists in the apparatus, said cover is held tightly upon its seat by the atmospheric prpssure upon the outer surface of said cover. v

Referring more particularly to the construction of the tubes F F, hereinbefore referred to, the inner tubes IF.

' are somewhat longer than the tubes F and are arranged with their upper and lower ends below the upper and lower ends of said tubes F. Said tubes 1- are held centrally in the tubes by means of three transversely disposed centering pins f f f which extend radially through the tubes F and project from the sides thereof are of a length equal to the interior diameter of the tubes F. The top and bottom pins f l and f are arranged in such a manner that the ends thereof contact with the inner walls of the tube F near the top and bottom of the pins f and f and its ends contact with the inner' faces of the tube F near the center thereof. By this construction, the inner tube F is prevented from moving laterally within the tube F and s'aid tubes are held in concentric relation to each other. The tubes F are supportcdwithin the tubes F by hangers f f, the upper ends ofwhichare outwardly curved and adapted to engage 'and rest upon the upper edges of the tubes F. In the lwer parts of said hangers, which depend from the uppez edges of the outer tubes, within the latter, are apertures for the reception of the ends of the upper cen- (cering pins f. i

The hangers arranged as described sustain the inner within the outer tubes in the position described, namely, with the top of each-tube F at a considerable distance below the top of the tube F. Inasmuch as the inner- -tubes F are longer than the outer tubes F, the loweneiids of said inner tubes will project downwardly into compartment D considerably below the lower an essential featurejof my invention and whilei'l have shown a simple and preferred form of construction in means for sustaining the inner within the outer tubes, 1 do not desire to belimited to the details of Cl11lstrn tion shown and described, as it is manifest that other means maybe employed for the purpose stated, with-- out dcparting'from the spirit of my invention.- V

tion is illustrated in Fig. 5 of the drawings. In the .form of my invention hereinbefore described,*the removal of the man-hole cover D, for the removal oi the urn pan and'destroys the existing 'vtgeuurn, so that the process of restoring said vacuum its; be effected as many times as it becomes necessaryto remove the accumulated salt. The apparatusis,- therefore, intermittont in its operation and the modification of-my in'-' volition is designed to make this operationcontinuous. To offset this result, the bottom wall A3 of the shell A is downwardly and inwardly extended so as to form a funnel, with an opening in the bottom thereol, which is-connected with a comparatively large valved conduit a". This is necessary in order to permit the manhole ends of the tubes F. This'arrangement of the tubes issaid tube F, while the pin-f is placed transversely to p Another form of vacuum pan embodying my inven-V precipitated salt, admits air into the interior of the vacu siderably less than the capacity of the vacuum pan..

When a quantity of salt'has accumulated in the compartmont D the valve in the conduit G may be opened. the salt allowed to descend and the valve then closed,

it being evident that the small amount of air entering the vacuum pan from the receptacle G to equalize the pressures therein will not substantially impair the partial vacuum in said pan. The salt is removed from the compartment G through a door G 1 A suitable valved drain-pipe G f may convenientlybe located at the bottom of the compartment G for draining off the liquid which passes in to said compartment with, the salt.

In order to completely describe the operation. of theapparatus, let it be assumed that the pan has been washed out by the inflow of water at the conduit a (Fig. 1). This water is allowed to pass out through the outlet pipe D, as before stated. The valves controlling the-pipes a, D and D and the air tight doors D" D are then closed. The valve 0 is opened and steam allowed to enter the pan and by its condensation effect a partial vacuum in the pan as above described. The spent lye, or material to be treated is then allowed to enter the compartment D, under pres sure if necessary, filling said compartment and rising through the tubes F and F, until the level of'the liquid or material reaches about six-inches above the top of the tubes F, or higher if desired. Steam then being admitted to the steam compartment, the liquid in cont act .with the inner walls of the tubes F is brought to the boiling point by the transmission therethrough otheat derived'from'the steam, and-said liquid being of less density than the liquid within the tubes F rises while the liquid within the tubes l5.

descendsl In this manner a continuous circulation oi the liquid takes place through all the tubes, the heated liquid rising through the passages between the. tubes and the cooler'liquid descending through the inner tubes F The liquid in passing out-of the lower ends of the tubes Fl mingles withthe liquid in the. compartment 1). and serves to heat the contents oi saigl' cornpar tmeiit. Such mingling oi the circulat ing liquid with the liquid, in the compartment l) is facilitated by the extension of the lower ends of the tubes F below the lower ends of tubes F. It is to be noted also that, as the liquid will descend through the tubes F ,with considerable force, it will serve to agitate the liquid below and bring the liquid near the bottom of the compartment D- incontact with'the cir- T culating liquid. l

I regard this construction. and arrangement oi the tubes as a great improvement inthe art, as con'tinuous circulation of the liqfiid through every tube absolutely prevents the clogging of the tubes by the precipitated salt, as iseomrnon in the operation of vacuum pans now in use.

tion through all the tubesals o insures a comparatively level deposit or accumulation of'thc precipitated salt and prevents the banking on one side which ordinarily results when part of the tubes become stopped or clogged or whichresults from irregular circulation. Moreover, the regular and uniform circulation through all the tubes prevents theliquid frour ioar'uing and This constant uniform circulaboiling over, asin other constructions which require numerous catch-ails and baffle-plates to prevent the liquid from passing out, and pipes to lead it back to the evaporating pan. In my improved apparatus,

the liquid rising in the space between tubes F and F,

on reaching the top of tube F descends through tube F into compartment D, thereby maintaining a perfeet circulation without disturbing the liquid above the tubes. As a result, violent ebullition and loss boiling over are prevented, and the capacity of '75 evaporator .increased. As an additional means oi -preventing any liquid from passing into the outlet pipe a during the boiling operation, I haveprovided the baflle-plates a and a. Any liquid or solid matter which may strike said baffle-plates falls back, while the gases and vapors pass into the space betweenthe baffle-plates u and a, and through'the' opening. a? to the outlet passage a. The liquid is subjected to this,

treatment for a period of time necessary to properly precipitate the contained salt and allow the gases, vapors, etc. to pass off'into the condenser and until the liquid is of the required density. The valve a" is then opened allowing air to enter the apparatus and destroy the vacuum therein, after which the manholecover I) i's'opened and the salt removed, and if necessary the pan flushed out. I It will be understood from the foregoing that while my improved device is adapted for the. evaporation of liquids containing salts or other solids in solution, and the recovery of said lids, it is equally well adapted for the partial-or cogplete evaporation of liquids not containing solids in solution and 'myi lvention covers an apparatus for partially or completely evaporating liquids of all kinds, whether they contain solids in so lution'or not. v I claim as my invention 1, A vacuum pad having anupp'er and a lower compel-t mentnnd'an intermediate steam-chest, a. plurality of circulating tubes passing through said steam-chest, said tubes affording communication-between said upper and lower compartments, and smaller auxiliary tubes located concentrically within each of said circulating tubes and communicating at their lower ends with said lower compertinent. said tubes having their upper ends not higher than the level of the upper ends of said circulating tubes.

2. A vacuum pan having an upper-"ands lower coui partment, and an intermediate steam-chest, a pluralityof circulating tubes passing through the sald fsteum-chest,

said tuhes afifm'dlng communication betwehf said"upper and lower compartments, and auxiliary tubes located concentricail y-withiu said circulating tubes, 'sald'anxillary tubes lthvjng their upper ends below the upper ends of said cirhu latlng tubes and communicating at their lower ends with said lower compartment. p

3. A vacuum pan having an upper and a'lower compart ientend an intermediate steam-ohest, a plurality of circulating tubes passing through said steam-chest, said tubes affording communication between said upperfa nd lo we'r compartments, and auxiliary tubes located within I said clrculatlngtubes, the upper ends of said auxiliary tubes beingimlnw the upper ends or the large circulating tubes, and the lower ends ofsuid auxiliary tubes depending below the lower ends of said circulating tubes and "opening into said lower compartment.

4. 'A vacuum pan havin an upper and a lower compartment and an intermediate steam-chest, a plurality of circulating tubes passing through the said steam-chest,

said tubes affording communication between said upper and 1 wer compartments, auxlllar tubes locatedwithin each or said circulating tubes, an ,meuns for supporting the auxiliary tubes in said circulating tubes embracing hangers having hooked upper ends engaging the upper margins of said circulating tubes.

5. A vacuum pan having an upper and a lower compartment and an intermediate siemmchest, a plurality ot circulating tubes passing through the said steam-chest, said tubes affording communic'aiion between said upper and lower compartments, and auxiliary tubes located centrally within each of said circulating tubes; said auxiliary tubes 10 being each provided with a plurality of radially extending 

